scholarly journals Insight into the factors controlling the equilibrium of allylic azides

RSC Advances ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 4404-4413
Author(s):  
Margarita M. Vallejos ◽  
Guillermo R. Labadie

The factors controlling the allyl azides equilibrium has been studied by different theoretical approaches setting the basis to predict the regioisomers predominance in the equilibrium mixture.

2019 ◽  
Author(s):  
Margarita Vallejos ◽  
Guillermo Labadie

<p>Several allylic azides with different double bond substitution were studied to understand the factors governing their equilibrium using density functional theory along with quantum theory of atoms in molecules, Non-covalent Interactions and Natural Bond Orbitals approaches. The results showed the hydroxyl group or heteroatoms in allylic azides interact with the molecule through an electrostatic weak interaction in each pair of regioisomers. The equilibrium shifts of substituted allylic azides, compared to non-substituted allylic azides, are not attributed to the presence of specific interactions, such as hydrogen bond. The observed equilibrium shifts stem mainly from the strengthening and weakening of negative hyperconjugative interactions, which is affected by the weak interaction involving the proximal substituent in each regioisomer. A good linear correlation was obtained between the hyperconjugative energies of pC=C→s*<i>Z</i><sub>b</sub> interactions and the calculated percentages of secondary azide and tertiary azides in the equilibrium mixture. Also, the effect of aromatic ring substituent was analysed using such approaches. This study not only provides insight into the factor controlling the stabilities of the substituted allylic azides, but also settle the basis to predict the regioisomer predominance in the equilibrium mixture.</p>


2019 ◽  
Author(s):  
Margarita Vallejos ◽  
Guillermo Labadie

<p>Several allylic azides with different double bond substitution were studied to understand the factors governing their equilibrium using density functional theory along with quantum theory of atoms in molecules, Non-covalent Interactions and Natural Bond Orbitals approaches. The results showed the hydroxyl group or heteroatoms in allylic azides interact with the molecule through an electrostatic weak interaction in each pair of regioisomers. The equilibrium shifts of substituted allylic azides, compared to non-substituted allylic azides, are not attributed to the presence of specific interactions, such as hydrogen bond. The observed equilibrium shifts stem mainly from the strengthening and weakening of negative hyperconjugative interactions, which is affected by the weak interaction involving the proximal substituent in each regioisomer. A good linear correlation was obtained between the hyperconjugative energies of pC=C→s*<i>Z</i><sub>b</sub> interactions and the calculated percentages of secondary azide and tertiary azides in the equilibrium mixture. Also, the effect of aromatic ring substituent was analysed using such approaches. This study not only provides insight into the factor controlling the stabilities of the substituted allylic azides, but also settle the basis to predict the regioisomer predominance in the equilibrium mixture.</p>


2018 ◽  
Vol 14 (1) ◽  
pp. 25-43 ◽  
Author(s):  
Björn Technau

Abstract Ethnic slur terms (“nigger”, “kike”, “kraut”) and other group-based slurs (“faggot”, “spaz”) must be differentiated from general pejoratives (“asshole”, “idiot”) and pure expressives (“fuck”). As these terms pejoratively refer to certain groups of people, they are a typical feature of hate speech contexts where they serve xenophobic speakers in expressing their hatred for an entire group of people. However, slur terms are actually far more frequently used in other contexts and are more often exchanged among friends than between enemies. Hate speech can be identified as the most central, albeit not the most frequent, mode of use. I broadly distinguish between hate speech (central use), other pejorative uses (mobbing, insulting), parasitic uses (banter, appropriation, comedy, youth language), neutral mentioning (academics, PC), and unaware uses. In this paper, authentic examples of use and frequency estimates from empirical research will help provide accurate definitions and insight into these different modes that purely theoretical approaches cannot achieve.


Ars Adriatica ◽  
2017 ◽  
Vol 7 (1) ◽  
pp. 379
Author(s):  
Blaženka Perica

The collection of texts Image and Anti-Image – Julije Knifer and the Problem of Representation is based on multi- and transdisciplinary research conducted by Croatian and international critics and theoreticians. They have investigated the contemporary sensibility for the questions of image and pictoriality by referring to a common starting point: the oeuvre of one of the most important Croatian artists – Julije Knifer. In their analysis of Knifer’s paintings since the early 1960s, which revolve around a single motif – the “meander” – which the artist has repeated and varied throughout his artistic career, the authors have followed the changing reception of his work from the supremacy of the high modernist image concept, such as postulated in Greenberg’s formalistic theory, until today, when theoretical proposals have become essentially different. In his introduction to the project, editor Krešimir Purgar has stressed the importance of new perspectives that Knifer’s work may offer if viewed in the context of new disciplines such as visual studies and image science. The 21 articles, grouped into five thematic sections, aim at clarifying and expanding the references of Knifer’s “meander” by taking diverse informative and original approaches that have this recent image theory as their starting point. In the context of Croatian scholarly output, this publication is notable for having accomplished a rare blend between monographic material and a series of interdisciplinary, scholarly-theoretical studies based on extremely varied perspectives, resulting in a valuable comparative miscellany, a contribution both to the actualisation and new positioning of Knifer’s art and to our insight into various analytic and interpretative approaches related to the present state of art theory. Such an approach assigns a special place to the image, to pictoriality and visuality. The theoretical perspectives of image science and the heterogeneous, plural strategies of research developed within the new image studies (image science, visual studies) assimilate and expand rather than replace the previously accepted methods, common in traditional theoretical approaches to the discipline of art history.


Author(s):  
Елена Владимировна Грибоносова-Гребнева

В статье представлена работа В.А. Фаворского над киргизским героическим эпосом Манас. В серии созданных художником рисунков нашли проявление его художественные и теоретические подходы к искусству графики и иллюстрирования книг. Для более глубокого проникновения в суть эпического произведения художник отправляется в Киргизию. Созданные им рисунки имеют не только эстетическую и этнографическую ценности. В них проявилась его теория графики, когда белый фон бумаги воспринимается в качестве белого пространства, а карандаш художника становится сродни резцу скульптора. Пространство белого повисает на штрихах рисунка. Эпический характер повествования привел к монументальности образов и композиций иллюстраций. В статье приводятся теоретические мысли художника о соединении разновременных состояний в произведении искусства, роли контура и пятна. The work of V.A. Favorsky on the Kirghiz heroic epos is presented in this article. There is a demonstration of his artistic and theoretical approaches to the graphic arts and books illustration in the series of these drawings. The artist goes to Kyrgyzstan for the deep insight into the essence of the epic work. His drawings have not only aesthetic and ethnographic value. His theory of graphic appeared there, when a white field of paper is taken as a white space, and the artists pencil became similar to a cutter of a sculpture. The space of the white paper hangs on the drawings strokes. The epic nature of the narrative led to the monumentality of the images and compositions of the illustrations. There are artists theoretical thoughts about the connection of the multitemporal conditions in the works of art, the role of contour and spot.


2015 ◽  
Vol 23 (4) ◽  
pp. 363-373 ◽  
Author(s):  
Lise-Lotte Holmgreen

Purpose – The purpose of this paper is to discuss why social media frames may exert substantial influence on the image of organisations and even trigger organisational crises. Design/methodology/approach – The study applies the theoretical approaches of crisis, framing and stakeholder theory to examine social media constructions of organisational behaviour. A recent case from the Danish restaurant industry exemplifies the structuring of social media frames and their impact on organisational image. Findings – The results of the study confirm the findings of previous studies but with the crucial addition that the power of social media frames is closely connected to their drawing on basic cultural and social beliefs that unite stakeholders across potentially different interests and identities. Research limitations/implications – The study is qualitative and applies a small dataset. To confirm the findings, further studies need to be conducted. Social implications – This paper sheds light on an issue which continues to be highly relevant for organisations. By gaining insight into the conceptual nature of frames and stakeholder motivations, which guide social-media entries, they may be better equipped for meeting the demands of the public and thus for preventing crises. Originality/value – This is a field of research that continues to develop concurrently with the development and spread of social media. By analysing in detail how frames are constructed, the study contributes to research in the field.


2017 ◽  

Researching cultural diversity is a central subject of social anthropology. 25 authors from institutes in Germany, Austria and Switzerland offer an insight into the subject, its contents and theoretical perspectives. The articles cover a variety of topics: the history of the discipline as well as basic theories and methods, subareas such as business or kinship anthropology, crosscutting issues such as anthropology of media, but also up-to-date specialised fields such as urban or development anthropology. The book is therefore invaluable for students and anyone interested in social anthropology who wants to open up fields of work, theoretical approaches and results of the subject.


Adaptation ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 139-160
Author(s):  
Lydia Nicholson

Abstract Adaptation studies theorists have debated the value and scope of fidelity criticism for decades, but the application of fidelity discourse from an adaptation practitioner perspective is vastly under-researched. Using a practice-based research strategy, this article describes how a consideration of fidelity discourse during the development of the web-series, Oh Hi There History, supported the development of the series as an adapted text and raised new questions about adaptation theory and practice. Oh Hi There History is an adaptation of the Founders and Survivors project’s research into Tasmanian convict history. This article considers the binary of in/fidelity in a practitioner context, analyses how fidelity taxonomies might be applied to the development of an adapted text, and explores the possibilities of applying through practice theoretical approaches to fidelity discourse around intertextuality and history-as-adaptation. By applying these theories in a new context, this article argues that practice-based research can provide new insight into fidelity discourse and new ways of understanding the role of fidelity in adaptation practice.


2016 ◽  
Vol 19 (2) ◽  
pp. 212-245 ◽  
Author(s):  
Roland Schäfer ◽  
Ulrike Sayatz

In this paper, we analyze written sentences containing the German particles obwohl (“although”) and weil (“because”). In standard written German, these particles embed clauses in verb-last constituent order, which is characteristic of subordinated clauses. In spoken and – as we show – nonstandard written German, they embed clauses in verb-second constituent order, which is characteristic of independent sentences. Our usage-based approach to the syntax – graphemics interface includes a large-scale corpus analysis of the patterns of punctuation in the nonstandard variants that provides clues to the syntactic structure and degree of sentential independence of the nonstandard variants. Our corpus study confirms and refines hypotheses from existing theoretical approaches by clearly showing that writers mark obwohl clauses with verb-second order systematically as independent sentences, whereas weil clauses with verb-second order are much less strongly marked as independent. This work suggests that similar corpus studies could provide deeper insight into the interplay between syntax and graphemics.


2003 ◽  
Vol 13 (3) ◽  
pp. 287-313 ◽  
Author(s):  
Nile Green

AbstractSince “visions appear material to spiritual persons only, the vulgar herd of historians and annalists cannot hope to be so favoured by Heaven”. So, in his nineteenth-century account of the sūfīs of Sind, Sir Richard Burton expressed the dilemma of scholars researching Muslim dream and visionary experiences in his characteristic style. But while scholarly discussion of the visionary activities of premodern sūfīs and other Muslims is still no straightforward matter we need no longer be deterred by Burton's sardonic pessimism. Despite the reticence of earlier generations of positivist scholarship, the past two decades have witnessed a flourishing of research into the visionary aspects of Muslim religious and cultural practice, chiefly through the analysis of the extensive literature surrounding the dream and vision in Islam. For, from the very beginning of Islamic history, there has developed a rich and varied discourse on the nature of the imagination and its expression in the form of dreams and waking visions. The theoretical approaches to the imagination developed by early Muslim philosophers and mystical theorists were always accompanied by the activities of a more active sodality of dreamers and vision seekers. For this reason, Islamic tradition is especially rich for its contributions to both theories of the imagination and the description of its expression in dream and visionary experience. The abundant yields from this rich research field in recent years afford new insight into the Muslim past, allowing an often intimate encounter with past individuals and private experiences scarcely granted by the analysis of other kinds of documentation.


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